US20140337784A1 - Portable device, method of detecting operation, and computer-readable storage medium storing program for detecting operation - Google Patents

Abstract

A mobile telephone includes a touch panel, an acceleration sensor which detects an acceleration, and an operation detection unit which detects a predetermined operation in accordance with the acceleration detected by the acceleration sensor while an instruction made by the touch panel is being detected. For this, it is possible to detect an operation to press the touch panel while a user finger is in contact with the touch panel.

Description

• This is a Continuation Application of U.S. patent application Ser. No. 13/126,075, filed Apr. 26, 2011, which is in turn a U.S. National Stage Application of PCT/JP2009/005638, filed Oct. 26, 2009, and claims priority of Japanese Application No. 2008-278146, filed Oct. 29, 2008. The disclosures of the prior applications are hereby incorporated by reference herein in its entirety.
Technical Field
• The present invention relates to a portable device, a method of detecting an operation, and a computer-readable storage medium storing a program for detecting an operation, and more particularly, to a portable device including atouch panel5, as well as a method of detecting an operation executed by such a portable device, and a computer-readable storage medium storing a program for detecting an operation executed by the same.
BACKGROUND ART
• Recently, mobile phones have appeared on the market having a liquid crystal display (hereinafter referred to as an “LCD”) and atouch panel5 placed upon it. The liquid crystal display displays an image including a plurality of keys, wheretouch panel5 detects an indication for one of the keys and receives the input of a number or a character (seePatent Document 1, for example). In such a mobile phone, inputting alphabet, hiragana or katakana involves allocating a plurality of characters to a key and receiving the input of one of the characters depending on the number of times the key is depressed consecutively.
• Whiletouch panel5 is capable of detecting a position indicated, if an operation involving a plurality of indications in one and the same position is to be detected bytouch panel5, the user must perform two operations: touchingtouch panel5 with a finger and then lifting the finger off the panel each time the key is depressed. As a result, operations can be troublesome.
• [Patent Document 1] Japanese Patent Laid-Open No. 2005-92441
DISCLOSURE OF THE INVENTIONProblems to be Solved by the Invention
• The present invention was made to solve this problem. An object of the present invention is to provide a portable device capable of detecting an operation in which a user depresses a touch panel while continuously touching the touch panel.
• Another object of the present invention is to provide a method of detecting an operation that allows detection of an operation in which a user depresses a touch panel while continuously touching the touch panel.
• Yet another object of the present invention is to provide a computer-readable storage medium storing a program for detecting an operation that allows detection of an operation in which a user depresses a touch panel while continuously touching the touch panel.
Means for Solving the Problems
• To achieve the above object, according to an aspect of the present invention, a portable device includes: a touch panel; an acceleration sensor detecting an acceleration value; and a detecting means detecting a specified operation based on an acceleration value detected by the acceleration sensor while an indication is being detected by the touch panel.
• According to another aspect of the present invention, a method of detecting an operation is performed by a portable device including a touch panel, including the steps of: detecting an acceleration value; and detecting a specified operation based on an acceleration value detected while an indication is being detected by the touch panel.
• According to yet another aspect of the present invention, a program for detecting an operation stored in a computer-readable storage medium is executed by a portable device including a touch panel, for causing a computer to execute the steps of detecting an acceleration value; and detecting a specified operation based on an acceleration value detected while an indication is being detected by the touch panel.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of an external appearance of a mobile phone according to an embodiment of the present invention.
• FIG. 2 is a functional block diagram showing an example of a set of functions of the mobile phone according to the present embodiment.
• FIG. 3 is a functional block diagram schematically showing functions of the control unit.
• FIG. 4 shows an example of a set of acceleration values A(n).
• FIG. 5 shows an example of a set of primary differential values B(n).
• FIG. 6 shows an example of a set of moving averages S(n).
• FIG. 7 shows an example of a set of secondary differential values B(n).
• FIG. 8 is a flow chart showing an example of a flow of a process for detecting an operation.
BEST MODES FOR CARRYING OUT THE INVENTION
• Now, an embodiment of the present invention will be described with reference to drawings. In the description below, like components are labeled with like reference characters, and have identical names and functions. Therefore, their detailed description will not be repeated.
• FIG. 1 is a perspective view of an external appearance of a mobile phone according to an embodiment of the present invention. Referring toFIG. 1, amobile phone1, which serves as a portable device, includes on its upper side an LCD3, atouch panel5 placed upon LCD3, aspeaker7 comprising a receiver, and amicrophone9. While the present embodiment shows amobile phone1 with an LCD3, LCD3 may be replaced with an organic EL (electroluminescence) display.
• Touch panel5 may be a pressure-sensitive panel, in which case changes in pressure are sensed, or may be an electrostatic panel, where electric signals generated by static electricity are sensed. If anelectrostatic touch panel5 is used,touch panel5 may be placed on the backside of LCD3. The present embodiment uses an electrostatic panel. When a user touchestouch panel5 with a finger,touch panel5 detects the position touched by the user with the finger as an indicated position. While the user is touchingtouch panel5 with the finger, the panel outputs the detected indicated position to acontrol unit11. If the user continues to indicate one and the same position, the same indicated position is output continuously to controlunit11. It should be noted that an indicated position may be output to controlunit11 at predetermined time intervals white the user is touchingtouch panel5 with the finger. In this case, too,control unit11 can detect the user continuously touchingtouch panel5 with the finger.
• FIG. 2 is a functional block diagram showing an example of a set of functions of the mobile phone according to the present embodiment. Referring toFIG. 2,mobile phone1 includes: acontrol unit11 for controlling the entiremobile phone1; aradio circuit13 connected to anantenna13A; acodec unit21 for processing audio data; amicrophone9 and aspeaker7 connected tocodec unit21; an LCD3; atouch panel5; a RAM (random-access memory)15 used as a working area forcontrol unit11; an EEPROM (electronically erasable and programmable read-only memory)17 for storing, for example, a program to be executed bycontrol unit11; anacceleration sensor19; avibration unit23; and a card interface (I/F)25.
• Radio circuit13 communicates wirelessly with a device at a base station connected to the communication network. A radio signal sent by a device at a base station is received byantenna13A.Radio circuit13 receives the radio signal received byantenna13A, and outputs the radio signal demodulated into an audio signal tocodec unit21.Radio circuit13 also receives an audio signal fromcodec unit21, and outputs the audio signal modulated into a radio signal toantenna13A. The radio signal sent fromantenna13A is received by a device at a base station.
• Codec unit21 decodes an audio signal input fromradio circuit13, converts the decoded digital audio signal to an analog one, amplifies it, and outputs it tospeaker7.Codec unit21 also receives an analog audio signal frommicrophone9, converts the audio signal to a digital one, encodes it, and outputs the encoded audio signal toradio circuit13.
• Adetachable flash memory27 is mounted on card I/F25.Control unit11 can accessflash memory27 via card I/F25. While in the present embodiment a program to be executed bycontrol unit11 is stored in EEPROM17, a program may be stored inflash memory27, from which the program may be read and executed bycontrol unit11. Such a storage medium storing a program does not have to beflash memory27 and may be a flexible disc, a cassette tape, an optical disc (CD-ROM (compact disc-ROM)/MO (magnetic optical disc)/MD (mini-disc)/DVD (digital versatile disc)), an IC card, an optical card, or a semiconductor memory such as a mask ROM, an EPROM (erasable programmable ROM), or an EEPROM (electronically EPROM).
• Also,mobile phone1 may be connected to the Internet viaradio circuit13, where a program may be downloaded from a computer connected to the Internet and be executed bycontrol unit11. Such a program does not have to be a program directly executable bycontrol unit11, but also includes a source program, a compressed program, an encrypted program or the like.
• Acceleration sensor19 detects acceleration and outputs the detected acceleration value tocontrol unit11. The direction of the acceleration value detected byacceleration sensor19 is the direction in whichmobile phone1 moves in a hand of the user who holds it when the user depressestouch panel5. Preferably, the acceleration value detected byacceleration sensor19 is in the direction perpendicular to the surface oftouch panel5. It should be noted that the direction perpendicular to the surface oftouch panel5 includes directions that are not exactly perpendicular due to a manufacturing error.
• FIG. 3 is a function block diagram schematically showing functions of the control unit. Referring toFIG. 3,control unit11 includes an indicatedposition receiving unit51 that receives an indicated position fromtouch panel5, anoperation detection unit53 that detects a specified operation, asignal determining unit55 that determines one signal out of a plurality of predetermined signals, and adisplay control unit57 that controls the display onLCD5.
• Display control unit57controls LCD7 and displays an image onLCD7. For the purposes of explanation, the present embodiment describes an image including a plurality of keys displayed onLCD7.Display control unit57 outputs, to signal determiningunit55, key information including a pair of items: name and area, for each of the keys contained in the image displayed onLCD7.
• Indicatedposition receiving unit51 receives an indicated position output fromtouch panel5, and outputs the received indicated position tooperation detection unit53 andsignal determining unit55. If the user continuously touches the surface oftouch panel5, indicatedposition receiving unit51 continuously outputs the indicated position tooperation detection unit53 andsignal determining unit55 as long as the user is touchingtouch panel5.
• While the user is holdingmobile phone1 in a hand,operation detection unit53 detects an operation in which the user depressestouch panel5 with a finger while continuously touchingtouch panel5 with the finger. When the user depressestouch panel5 with a finger while continuously touchingtouch panel5 with the finger, the upper surface ofmobile phone1, which hastouch panel5 mounted on it, is pressed, such thatmobile phone1 is moved in space by the user's hand. This movement may be a reciprocating motion in a direction generally perpendicular to the surface oftouch panel5, or may be reciprocating motion back and forth in a circular orbit around a wrist. Since the distance of movement of such a reciprocating motion is very small, the movement ofmobile phone1 is in a direction generally perpendicular to touchpanel5.Operation detection unit53 detects a reciprocating motion ofmobile phone1 based on an acceleration value input fromacceleration sensor19 while an indicated position is being input from indicatedposition receiving unit51, in order to detect an operation in which the user depressestouch panel5 with a finger while continuously touchingtouch panel5 with a finger.
• For this purpose,operation detection unit53 includes: anacceleration detecting unit61 that receives an acceleration value output byacceleration sensor19; a primarydifferential calculating unit63 that differentiates acceleration values; a movingaverage calculating unit65 that calculates the moving average of differentiated acceleration values; a secondarydifferential calculating unit67 that differentiate moving averages; a localmaximum extraction unit69 that extracts a local maximum for moving averages; a localminimum extraction unit71 that extracts a local minimum for moving averages; and adifference calculating unit73 that calculates the difference between a local maximum and a local minimum.
• Acceleration detecting unit61 receives an indicated position from indicatedposition receiving unit51, and an acceleration valueform acceleration sensor19. At predetermined intervals,acceleration detecting unit61 samples an acceleration value output byacceleration sensor19 while an indicated position is being input from indicatedposition receiving unit51, and outputs the sampled acceleration value to primarydifferential calculating unit63. An acceleration value output byacceleration detecting unit61 is denoted by A(n). The variable n is a positive integer and denotes a sampling point. When no indicated position is input from indicatedposition receiving unit51,acceleration detecting unit61 resets the variable n to “1” and, when an indicated position is then input from indicatedposition receiving unit51, initiates sampling and outputs an acceleration value A(n).FIG. 4 shows an example of a set of acceleration values A(n).
• Primarydifferential calculating unit63 differentiates acceleration values input fromacceleration detecting unit61. In this embodiment, the value obtained by differentiating acceleration values once is referred to as a primary differential value B(n). The primary differential value B(n) denotes a change in acceleration values A(n) and is suitably used for detecting a reciprocating motion ofmobile phone1. Specifically, a primary differential value B(n) can be calculated by using the following equation (1):
• 
  B(n)=(A(n+1)−A(n−1))/2   (1)
• Primarydifferential calculating unit63 outputs the calculated primary differential value B(n) to movingaverage calculating unit65.FIG. 5 shows an example of a set of primary differential values B(n). The primary differential values B(n) shown inFIG. 5 are primary differential values calculated based on the acceleration values A(n) shown inFIG. 4.
• Movingaverage calculating unit65 calculates a moving average of primary differential values B(n) for a predetermined time period. A moving average is calculated in order to remove noise. Particularly, it can remove vibrations with shorter cycles than vibrations from an operation in which the user depressestouch panel5 with a finger. Specifically, the moving average S(n), which is the average of six consecutive primary differential values, can be calculated by using the following equation (2):
• 
  S(n)=(B(n−5)+B(n−4)+B(n−3)+B(n−2)+B(n−1)+B(n))/6   (2)
• Movingaverage calculating unit65 outputs the calculated moving average S(n) to secondarydifferential calculating unit67, localmaximum extraction unit69 and localminimum extraction unit71.FIG. 6 shows an example of a set of moving averages S(n). The moving averages S(n) shown inFIG. 6 are moving averages calculated from the primary differential values B(n) shown inFIG. 5.
• It should be noted that, while in the present embodiment a moving average is the average of six consecutive primary differential values, the number of primary differential values that are moving-averaged can be determined by the time period suitable for the detection of changes in acceleration due to an operation in which the user depressestouch panel5 with a finger while continuously touchingtouch panel5 with the finger, and by the sampling cycle. The time period suitable for the detection of changes in acceleration due to an operation in which the used depressestouch panel5 with a finger while continuously touchingtouch panel5 with the finger can be determined by an experiment.
• Secondarydifferential calculating unit67 differentiates moving averages. In the present embodiment, the value obtained by differentiating moving averages once is referred to as a secondary differential value C(n). Specifically, the secondary differential value C(n) can be calculated by using the following equation (3):
• 
  C(n)=(S(n+1)−S(n−1))/2   (3)
• Secondarydifferential calculating unit67 outputs the calculated secondary differential value C(n) to localmaximum extraction unit69 and localminimum extraction unit71.FIG. 7 shows an example of a set of secondary differential values B(n). The secondary differential values C(n) shown inFIG. 7 are secondary differential values calculated based on the moving averages S(n) shown inFIG. 6. A secondary differential value C(n) is calculated in order to obtain an extremum of moving averages S(n). The sampling point at which the secondary differential value C(n) is closest to “0” indicates an extremum of moving averages S(n). Secondarydifferential calculating unit67 outputs, to localmaximum extraction unit69 and localminimum extraction unit71, the variable n that indicates the sampling point at which the secondary differential value C(n) comes closest to “0”. In this embodiment, the sampling point at which the secondary differential value C(n) comes closest to “0” is denoted by N.
• Localmaximum extraction unit69 receives a moving average S(n) from movingaverage calculating unit65, and a sampling point N from secondarydifferential calculating unit67. Localmaximum extraction unit69 extracts a large extremum from moving averages S(n). Specifically, if the moving average S(N) at the sampling point N input from secondarydifferential calculating unit67 is larger than the preceding moving average S(N−1), it is regarded as a local maximum. If the moving average S(N) at the sampling point N is regarded as a local maximum, localmaximum extraction unit69 outputs the moving average S(N) as a local maximum todifference calculating unit73.
• Localminimum extraction unit71 receives a moving average S(n) from movingaverage calculating unit65, and a sampling point N from secondarydifferential calculating unit67. Localminimum extraction unit71 extracts a local minimum from moving averages S(n). Specifically, if the moving average S(N) at the sampling point N input from secondarydifferential calculating unit67 is smaller than the preceding moving average S(N−1), it is regarded as a local minimum. If the moving average S(N) at the sampling point N is regarded as a local minimum, localminimum extraction unit71 outputs the moving average S(N) as a local minimum todifference calculating unit73.
• Difference calculating unit73 receives the local maximum from localmaximum extraction unit69, and the local minimum from the local minimum extraction unit.Difference calculating unit73 calculates the difference between the maximum and the minimum and compares the calculated difference with a threshold value. If the calculated difference is equal to or larger than the threshold value,difference calculating unit73 detects an operation in which the user depressestouch panel5 with a finger while continuously touching the panel (hereinafter referred to as a “depressing operation”), and outputs to signal determining unit55 a signal indicating that a depressing operation has been input. The threshold value is a predetermined value and can be obtained by an experiment. For example, if the user holdsmobile phone1 in a hand and depresses the surface oftouch panel5 with a finger,mobile phone1 is moved in space by the user's hand and reciprocates in a direction generally perpendicular to the surface oftouch panel5, in which case the threshold may be the smallest absolute value of the primary differential value of the acceleration values generated at that moment.
• Signal determiningunit55 receives key information fromdisplay control unit57, an indicated position from indicatedposition receiving unit51, and a signal indicating that a depressing operation has been input fromdifference calculating unit73. Signal determiningunit55 detects an indication by the user of one of the keys contained in the image displayed onLCD7 based on the key information input fromdisplay control unit57 and the indicated position input from indicatedposition receiving unit51. The description below will be made for three alphabetic characters: “A”, “B” and “C” allocated to the key indicated by the user.
• While an indicated position indicating the position of the key to which the three alphabetic characters are allocated is being continuously input from indicatedposition receiving unit51,signal determining unit55 counts the number of times a signal indicating that a depressing operation has been input is input fromdifference calculating unit73. A key table that associates the alphabetic characters allocated to the keys contained in the image displayed on LCD3 with the numbers of indications is stored inEEPROM17 beforehand. Signal determiningunit55 refers to the key table to determine a character, which depends on the key identified by the indicated position and the number counted. For example, while an indicated position indicating the position of the key to which “ABC” is allocated is being continuously input, the unit selects the character “A” out of the characters “A”, “B” and “C” if a signal indicating that a depressing operation has been input is input once, selects the character “B” if such a signal is input twice, and selects the character “C” if such a signal is input three times. Each timesignal determining unit55 selects a character, it determines the selected character as the character to be displayed, for example, stores it in a predetermined area ofRAM15 and displays it in a predetermined area of LCD3.
• FIG. 8 is a flow chart showing an example of a flow of a process for detecting an operation. The operation detecting process is executed bycontrol unit11 included inmobile phone1, wherecontrol unit11 executes an operation detecting program. Referring toFIG. 8,control unit11 is on standby (NO at step S01) until it detects an indication that the user touchestouch panel5, and when it detects an indication that the user touches touch panel5 (YES at step01), the process proceeds to step S02. When an indicated position is input fromtouch panel5,control unit11 detects an indication that the user touchestouch panel5. In other words, the operation detecting process is executed on condition that the user touchestouch panel5.
• At step S02, the variable n is set to “1” and the other variables are initialized. The variables that are initialized at this moment include the stop counter C1, the operation counter C2, the local maximum MAX, the local minimum MIN, the array of acceleration values A(n), the array of primary differential values B(n), the array of moving averages S(n), and the array of secondary differential values C(n); they are set to “0”.
• At step S03, the acceleration value output byacceleration sensor19 is acquired, and the array of acceleration values A(n) is set to the acquired acceleration values.
• At step S04, it is determined whether an indication that the user touchestouch panel5 has been detected, similar to step S01. If an indication by the user has been detected, the process proceeds to step S05; if not, the process ends. That is, the operation detection process detects an operation in which the user depressestouch panel5 with a finger from the moment the user's finger gets in contact withtouch panel5 until it lifts offtouch panel5.
• At step S05, it is determined whether the variable n is larger than “2”. If the variable n is larger than “2”, the process proceeds to step S06; if not, the process proceeds to step S22. Step S06 and the subsequent steps are performed if the variable n is larger than “2” in order to calculate a primary differential value at step S06. At step S22, the variable n is incremented by “1”, and the process proceeds to step S03.
• At step S06, a primary differential variable is calculated, and the array B(n) is set to calculated primary differential values. Specifically, a primary differential value is calculated by using the above equation (1) from the acceleration value A(n−1) and the acceleration value A(n+1).
• At step S07, it is determined whether the variable n is larger than “7”. If the variable n is larger than “7”, the process proceeds to step S08; if not, the process proceeds to step S22. Step S08 and the subsequent steps are performed if the variable n is larger than “7” in order to calculate a moving average at step S08. At step S22, the variable n is incremented by “1”, and the process returns to step S03.
• At step S08, a moving average of primary differential values is calculated, and the array S(n) is set to calculated moving averages. Specifically, a moving average is calculated by using the above equation (2) from the primary differential values B(n−5), B(n−4), B(n−3), B(n−2), B(n−1) and B(n).
• At the next step, S09, it is determined whether the absolute value of a calculated moving average S(n) is equal to or smaller than the threshold value T1. If the absolute value of a moving average S(n) is equal to or smaller than the threshold T1, the process proceeds to step S10; if not, the process proceeds to step S12. At step S10, the stop counter C1 is incremented by “1”, and the process proceeds to step S11. At step S11, it is determined whether the stop counter C1 is larger than the threshold value P. If the stop counter C1 is larger than the threshold value P, the process ends; if not, the process proceeds to step S12. The stop counter C1 counts the number of times the absolute value of a moving average S(n) is equal to or smaller than the threshold value T1 in a row. If the stop counter C1 is larger than the threshold value P, the process ends; thus, the process ends when the absolute value of a moving average S(n) is equal to or smaller than the threshold value T1 P times or more often in a row. If the absolute value of a moving average S(n) is equal to or smaller than the threshold value T1, it means that acceleration remains unchanged; if this state persists for a certain period of time, it means that no operation is being input tomobile phone1 or the mobile phone is not held in a hand and lies on a desk, for example; thus, it is determined thatmobile phone1 is not being operated.
• At step S12, it is determined whether the variable n is larger than “9”. If the variable n is larger than “9”, the process proceeds to step S13; if not, the process proceeds to step S22. Step S13 and the subsequent steps are performed if the variable n is larger than “9” in order to calculate a secondary differential value based on moving averages at step S13. At step S22, the variable n is incremented by “1”, and the process returns to step S03.
• At step S13, a differential value is calculated from moving averages S(n), and the array C(n) is set to calculated differential values. Specifically, a differential value is calculated by using the above equation (3) from the moving average S(n−1) and the moving average S(n+1). In the present embodiment, a differential value that can be obtained by differentiating moving averages S(n) is denoted by a secondary differential value C(n).
• At step S14, it is determined whether the secondary differential value C(n) is “0”. It should be noted that the C(n) may not be “0” for some sampling points, in which case, in order to determine whether the C(n) is “0”, it may be determined whether the C(n) is closest to “0”. If the secondary differential value C(n) is “0”, the process proceeds to step S15; if not, the process proceeds to step S22. If the secondary differential value C(n) is “0”, the moving average S(n) is at a local maximum or a local minimum.
• At step S15, the moving averages S(n) and S(n−1) are compared with each other. If the moving average S(n) is larger than the moving average S(n−1), the process proceeds to step S16; if not, the process proceeds to step S17. At step S16, the local maximum MAX, a variable to which the local maximum can be set, is set to the moving average S(n), and the process proceeds to step S18. On the other hand, at step S17, the local maximum MIN, a variable to which the local maximum can be set, is set to the moving average S(n), and the process proceeds to step S18.
• At step S18, the difference between the local maximum MAX and the local minimum MIN is calculated, and it is determined whether that difference is larger than the threshold value T2. If the difference is larger than the threshold value T2, the process proceeds to step S19; if not, the process proceeds to step S22. At step S19, the operation counter C2 is incremented by “1”. Thus, when the difference between a local maximum and a local minimum is equal to or larger than the threshold value T2, one operation in which the user depressestouch panel5 with a finger is detected, thereby removing vibrations unrelated to a vibration that is caused by an operation in which the user depressestouch panel5 with a finger. Then, at step S20, the variables MAX, MIN and C1 are set to “0”, and the process proceeds to step S21.
• At step S21, a character is determined based on an indicated position input fromtouch panel5 and a value in the operation counter C2, and the process proceeds to step S22. At step S22, the variable n is incremented by “1”, and the process returns to step S03. Specifically, a key indicated by the user is identified based on key information including the pair of items: name and area for each of the keys contained in the image displayed on LCD3 and on the indicated position input fromtouch panel5, and the identified key and the key table are used to determine the set of characters that have been allocated to the identified key; then, out of the set of characters, the character corresponding to the number of operations is determined. The number of operations is the value in the operation counter C2.
• With reference to the acceleration values shown inFIG. 4, a first vibration at sampling points1-8, a second vibration at sampling points8-21 and a third vibration at sampling points22-33 are shown. The first vibration is at its maximum at sampling point4, and at its minimum atsampling point7; the second vibration is at its maximum atsampling point14, and at its minimum atsampling point20; and the third vibration is at its maximum atsampling point27, and at its minimum at sampling point32.
• On the other hand, referring toFIG. 6, moving averages are shown with a first vibration at sampling points7-10, a second vibration at sampling points11-22 and a third vibration at sampling points23-35. The first vibration is at its maximum atsampling point7, and at its minimum atsampling point9. The difference between the local maximum and the local minimum is smaller than the threshold value T2, such that an operation in which the user depressestouch panel5 with a finger is not detected.
• The second vibration is at its maximum atsampling point13, and at its minimum atsampling point19. The difference between the local maximum and the local minimum is larger than the threshold value T2, such that an operation in which the user depressestouch panel5 with a finger is detected. The third vibration is at its maximum at sampling point26, and at its minimum at sampling point32. The difference between the local maximum and the local minimum is larger than the threshold value T2, such that an operation in which the user depressestouch panel5 with a finger is detected.
• Thus, as described above,mobile phone1, which serves as a portable device according to the present embodiment, detects an operation in which the user depressestouch panel5 while continuously touchingtouch panel5 based on an acceleration value detected while an indication ontouch panel5 is being detected, allowing the user to input an operation in which the user depresses one and the same position on the touch panel several times.
• Further, a specified operation is detected when the difference between a local maximum and a local minimum of differential values of acceleration values is equal to or larger than a predetermined threshold value, allowing detecting one operation based on one cycle of vibration generated by an operation in which the user depressestouch panel5 with continuously touchingtouch panel5.
• Also, the detecting means calculates a moving average of differential values output fromacceleration sensor19 for a predetermined period of time and calculates the difference between a local maximum and a subsequent local minimum of moving averages, thereby reducing noise contained in the detected acceleration values. Particularly, it may reduce a signal different from a vibration generated by an operation in which the user depressestouch panel5 while continuously touchingtouch panel5.
• Further, one character is determined out of a plurality of characters based on an indicated position detected bytouch panel5 and a number of times an operation in which the user depressestouch panel5 while continuously touchingtouch panel5 is detected, thereby allowing the user to select one character from a plurality of characters by just performing an operation(s) in which the user depresses one and the same position.
• Also,acceleration sensor19 is disposed in such a way that it can detect an acceleration value in the direction perpendicular to the panel surface oftouch panel5, thereby detecting a vibration generated by an operation in which the user depressestouch panel5 while continuously touchingtouch panel5.
• While the above embodiment describes amobile phone1 that serves as one example of a portable device, the present invention can, of course, be understood as including a method of detecting an operation for causingmobile phone1 to perform the process for detecting an operation shown inFIG. 8, or a program for detecting an operation for causing control unit11 (i.e. a computer) included inmobile phone1 to perform that method.
• It should be understood that the embodiments disclosed above are exemplary only and not restrictive in any way. The scope of the present invention is indicated not by the above description but by the Claims, and all the modifications equivalent in meaning to and within the Claims are intended to be included.

Claims (9)

1. A portable device comprising:

a display configured to display a plurality of keys, a plurality of characters being allocated to each of the plurality of keys;

a touch panel configured to detect whether each of the plurality of keys is touched;

an acceleration sensor that detects an acceleration value; and

a detecting module that detects a specified operation based on the acceleration value detected by the acceleration sensor, wherein

when the specified operation is detected one or more times by the detecting module while the touch panel detects that one of the plurality of keys is continued to be touched, the display displays a character selected from the plurality of characters based on the key continued to be touched and the number of times of the specified operation.

2. The portable device according toclaim 1, wherein the detecting module detects the specified operation when a difference between a local maximum and a local minimum of differential values of acceleration values is equal to or larger than a predetermined threshold value.

3. The portable device according toclaim 2, wherein the detecting module includes a moving average module that calculates a moving average of differential values output from the acceleration sensor for predetermined period of time to calculate a difference between the local maximum and a subsequent local minimum of calculated moving averages.

4. The portable device according toclaim 1, wherein the acceleration sensor detects the acceleration value in a direction perpendicular to a panel surface of the touch panel.

5. A method of detecting an operation performed by a portable device including a display and a touch panel, comprising the steps of:

displaying a plurality of keys, a plurality of characters being allocated to each of the plurality of keys;

detecting whether one of the plurality of keys is touched, the step being performed by the touch panel;

detecting an acceleration value;

detecting a specified operation based on the acceleration value detected; and

when the specified operation is detected one or more times by the detecting step while it is detected that the one of the plurality of keys is continued to be touched, displaying a character selected from the plurality of characters based on the key continued to be touched and the number of times of the specified operation, the displaying step being performed by the display.

6. The method of detecting the operation according toclaim 5, wherein the step of detecting includes the step of detecting the specified operation when a difference between a local maximum and a local minimum of differential values of acceleration values is equal to or larger than a predetermined threshold value.

7. The method of detecting the operation according toclaim 6, wherein the step of detecting includes the steps of:

calculating a moving average of differential values of acceleration values for a predetermined period of time; and

calculating a difference between the local maximum and a subsequent local minimum of calculated moving averages.

8. The method of detecting the operation according toclaim 6, wherein the acceleration value detected in the step of detecting is in a direction perpendicular to a panel surface of the touch panel.

9. A non-transitory computer-readable storage medium storing a program for detecting an operation executed by a portable device including a display and a touch panel, for causing a computer to execute the steps of:

displaying a plurality of keys, a plurality of characters being allocated to each of the plurality of keys;

detecting whether one of the plurality of keys is touched, the step being performed by the touch panel;

detecting an acceleration value;

detecting a specified operation based on the acceleration value detected; and

when the specified operation is detected one or more times by the detecting step while it is detected that the one of the plurality of keys is continued to be touched, displaying a character selected from the plurality of characters based on the key continued to be touched and the number of times of the specified operation, the displaying step being performed by the display.

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